PYONGYANG (AFP, REUTERS) - North Korean leader Kim Jong Un said on Friday (May 6) that "unprecedented results have been accomplished" with the "great success" of its January test of a nuclear weapon and February rocket launch of a satellite into space.

Kim, wearing a dark western-style suit and grey tie, made the remarks at the opening of the seventh Workers' Party congress in Pyongyang, according to North Korea's state television KRT.

Pyongyang had kicked off its first ruling party congress for nearly 40 years Friday, with state media lauding the isolated country's "prestige" as a nuclear power while maintaining a news blackout on the event itself.

The congress drew thousands of selected delegates from across the country to Pyongyang for what, in theory at least, was a gathering of North Korea's top decision-making body.

It also drew around 130 foreign journalists who were invited to cover the event but not allowed inside the venue, restricted instead to watching from a spot 200m away in the light drizzle falling on the capital.

And state television provided no live coverage, devoting its programming to archive material, films and patriotic concerts.

The 33-year-old Kim, who was not even born when the last Workers' Party Congress was held in 1980, was believed to have opened the conclave with a keynote address which, when published, will be scrutinised for any sign of a substantive policy shift, especially on the economic front.

Analysts will also be watching for personnel changes as Kim looks to bring in a younger generation of leaders hand-picked for their loyalty.

State media previewed the event by hailing the North's most recent nuclear test in January as evidence of its "greatness and prestige as a nuclear power state." And the North's Committee for the Peaceful Reunification of Korea slammed the international community's opposition to Pyongyang's nuclear weapons programme.

"Regardless of whether someone recognises it or not, our status as a nuclear state that is armed with H-bombs cannot change," the committee said in a statement.

There has been widespread speculation about the North preparing another nuclear test to coincide with the congress, as a defiant gesture of strength and future intent.

The 1980 event was staged to crown Kim's father Kim Jong Il as heir apparent to his own father, the North's founding leader Kim Il-Sung.

The 2016 version was being held inside the imposing April 25 Palace, whose stone facade was adorned with huge portraits of the two late leaders, along with giant red and gold ruling party banners.

While the agenda - and even the duration - of the congress remains unknown, its main objective is clearly to confirm Kim Jong Un's status as legitimate inheritor of the Kim family's dynastic rule which spans almost seven decades.

It may also enshrine as formal party doctrine Kim's "byungjin" policy of pursuing nuclear weapons in tandem with economic development.

Notably absent was any Chinese representation - a possible reflection of the increasingly strained ties between the North and its sole major ally.

A large Chinese delegation had attended the 1980 gathering, headed by Li Xiannian, later China's official head of state.

The North Korean capital was immaculately primped and primed for the congress, with national and Workers' Party flags lining its broad rainswept streets, along with banners carrying slogans such as "Great comrades Kim Il Sung and Kim Jong Il will always be with us".

Preparation had involved mobilising the entire country in a 70-day campaign that New York-based Human Rights Watch denounced as a mass exercise in forced labour.

The foreign media was accompanied by official minders, and passers-by who agreed to be interviewed stuck closely to the official line.

Office worker Kim Hyang, 26, said the North's nuclear arsenal was the unavoidable product of US aggression.

"They threaten the North with nuclear weapons, so if we are to defend our sovereignty, peace and security, we must have nuclear weapons," Kim said.

Since Kim took power after the death of his father in December 2011, North Korea has carried out two nuclear tests and two successful space rocket launches that.

Even as the international community responded with tougher sanctions, he pressed ahead with a single-minded drive for a credible nuclear deterrent with additional missile and technical tests.

He also demonstrated a ruthless streak, purging the party, government and powerful military of those seen as disloyal, and ordering the execution of his powerful uncle, and one-time political mentor, Jang SongThaek.